Hedgerow management and birds on organic farms S15
Elm Farm Research Centre, Newbury, RG20 0HR, UK.
|Hedges are important in the farm environment,
their wildlife habitat value is affected by the way in which they are managed, the
ecological implications of poor hedgerow structure can be substantial. The intensification
of conventional agriculture has been associated with two trends: widespread removal of
hedges to maximise production in larger fields and an increasing degree of neglect of the
remaining hedgerows, with management practices effectively rendering them useless as a
Standards for organic farming may include detailed management requirements for non-crop habitats including hedges, woodland, conservation areas etc.(for example see UKROFS, 1991). A study of bird populations on organic and conventional farms (Chamberlainet al, 1996) showed that there were significantly higher populations of birds on organic than on neighbouring, paired conventional farms. Hedges on organic farms were wider, taller and contained more trees than on the conventional farms where fields were larger (less hedgerow length per hectare) and hedges more frequently trimmed. Hedgerow management, crop type and in-crop diversity were responsible for the differences in bird populations observed between the organic and conventional farms. A survey of hedgerows at Elm Farm over an eleven year period (1983 - 1994), during which the farm was converted to an organic system showed that overall species richness increased (10% more species after 11 years), with a wider range of species observed across all hedges (Stopes et al, 1996). Hedges should reach a minimum size (at least 3m wide and 4m high), and be allowed to flower and fruit by operating a cutting frequency determined by the species present and the equipment used (every 2-5 years). Acombination of hedgerow management strategies over time throughout the farm can provide a diversity of non-crop habitats. These results show that organic management contributes to habitat quality and biodiversity.
Chamberlain, D., Fuller, R., Brooks, D. (1996) The Effects of OrganicFarming on Birds. Elm Farm Research Centre Bulletin, 21, p. 5-9. Newbury,UK. January 1996.
Stopes, C., Measures, M., Smith, C., Foster, L. (1996): Hedgerow management in organic farming - impact on biodiversity. In: Isart, J.,Llerena, J.J. (eds.) Biodiversity and land use: The role of organic farming. Proceedings of the First ENOF Workshop, Bonn, December 1995.
UKROFS (1991): UKROFS Standards for Organic Agriculture. United Kingdom Register of Organic Food Standards, Ministry of Agriculture, Fisheries andFood, London.